This invention relates generally to engine-driven generators and, more particularly, to alternating current (AC) synchronous alternators including structure for charging an engine starting battery.
Although small engine-driven electrical generators can be, and typically are hand started, larger units are typically started by means of a battery-powered starter motor. The starter battery is kept charged with a charging current developed by the generator as the generator operates.
In one common arrangement, a separate, dedicated alternator was included with the generator and was used to charge the starting battery. Although effective, the use of a separate alternator for battery charging was expensive and contributed to the size and weight of the generator.
In another arrangement, battery charging current was supplied from the main alternator windings of an AC synchronous alternator. Although generally effective, the battery charge voltage and, hence, the battery charge current, varied according to the load on the main alternator winding. Over or under charging could be the result.